Interesting I have been having an issue with mechanical noise with a 1KW transformer and the manufacture mentioned the possibility rectifiers causing it. I kind of blew it off as passing blame but I may revisit it. I am disappointed there has not been more feedback on JX progress I have wanted to build an X amp but missed out on initial buy. I am curious how this design manages with offset.
Bill
Bill
Hi,
How did you sink the MUR860's? what size were the TO-220 heatsinks?
are you using the briangt aleph psu boards? I'll be using this board
with MURF1620 and 2.5" TO-220 heatsinks. I hope I don't run into the same
problem. I would think the heatsinks are fine since the briangt psu
boards were designed for aleph 30/aleph 5 use.
I just got my antek 18V 600VA transformer. will advise if hum/buzz is noted.
With the BrianGT boards MUR860 may work more easily since it has room for board mounted heatsinks.
I was running mine without any sinks at all, I'm using Peter Daniel's power supply boards and the rectifier section is scored so it can be snapped off and then you would have lots of heatsinking options, bend the rectifiers over and mount to the chassis or amp heatsink, etc. I just didn't feel like tearing down my amp yet again to drill more holes and I had the heavier duty bridge rectifiers on hand so I used those.
I initially did that when I was running 1 power supply board for 2 channels, with 1 board per channel the MUR860 would probably run a lot cooler and might be just fine, I don't know for sure though.
I was running mine without any sinks at all, I'm using Peter Daniel's power supply boards and the rectifier section is scored so it can be snapped off and then you would have lots of heatsinking options, bend the rectifiers over and mount to the chassis or amp heatsink, etc. I just didn't feel like tearing down my amp yet again to drill more holes and I had the heavier duty bridge rectifiers on hand so I used those.
I initially did that when I was running 1 power supply board for 2 channels, with 1 board per channel the MUR860 would probably run a lot cooler and might be just fine, I don't know for sure though.
The MUR860's should work just fine as long as you heatsink them properly.
They should heat up pretty quick since the spec. says 1.5V drop.
I believe you are losing about 3V just from these diodes alone.
You might want to check the bridge rectifiers as well for their voltage drop.
Lower drop, less heat, more voltage at the rails.
AJ grounding scheme
I thought I had this figured out, but after reading recent posts, I rewired my stereo J's grounding and now the hum has returned. Perhaps someone can tell me the proper grounding scheme at a real basic level. I am using Peter Daniel's signal and power boards and am using rca inputs exclusively (don't even have XLR's on the chassis). So rca center pin goes to PD in+. Rca shield goes to PD- and is jumpered to SG on PD board. PD board 'out' goes to red binding post. Black binding post goes to other side of CL60, which in turn is connected to chassis screw which is earth grounded to ground lead of power cord. Power supply ground also goes to signal ground side of CL60. This configuration hums. I avoided hum by lifting the ground connection between black binding posts and signal ground, and instead wiring black binding posts to ground/signal ground (circuit traces are connected) on PD board. However, this does not ground the circuit - the ground is kept only from the RCA shield. I have tried to attach a picture to help visualize. If someone would kindly help... thanks!
I thought I had this figured out, but after reading recent posts, I rewired my stereo J's grounding and now the hum has returned. Perhaps someone can tell me the proper grounding scheme at a real basic level. I am using Peter Daniel's signal and power boards and am using rca inputs exclusively (don't even have XLR's on the chassis). So rca center pin goes to PD in+. Rca shield goes to PD- and is jumpered to SG on PD board. PD board 'out' goes to red binding post. Black binding post goes to other side of CL60, which in turn is connected to chassis screw which is earth grounded to ground lead of power cord. Power supply ground also goes to signal ground side of CL60. This configuration hums. I avoided hum by lifting the ground connection between black binding posts and signal ground, and instead wiring black binding posts to ground/signal ground (circuit traces are connected) on PD board. However, this does not ground the circuit - the ground is kept only from the RCA shield. I have tried to attach a picture to help visualize. If someone would kindly help... thanks!
Attachments
understanding star grounding
http://www.diyaudio.com/forums/chip...g-star-grounding.html?perpage=25&pagenumber=1
....maybe some helpful info here.
http://www.diyaudio.com/forums/chip...g-star-grounding.html?perpage=25&pagenumber=1
....maybe some helpful info here.
Hello Peter,
I am finishing assembly on my Aleph JX and I am kind of blanked out. For the CCS I am using j74. What is the value for Rp? P1 trimmer value is between 25 and 100 ohms, I believe based on EUVIL's post - please confirm.
Next, I am not sure is what is going on with R5 - is this resistor used or not if I am using j74.
Since i am using j74 I know that I do not need to populate CCS on the right size of daughter board, and than in that case C4, Z1 are not used?
Please confirm,
Thank you very much
AR2
I am finishing assembly on my Aleph JX and I am kind of blanked out. For the CCS I am using j74. What is the value for Rp? P1 trimmer value is between 25 and 100 ohms, I believe based on EUVIL's post - please confirm.
Next, I am not sure is what is going on with R5 - is this resistor used or not if I am using j74.
Since i am using j74 I know that I do not need to populate CCS on the right size of daughter board, and than in that case C4, Z1 are not used?
Please confirm,
Thank you very much
AR2
Vitalica
Be careful with the new Holco resisters , they sound as a PC of crap.
They no longer made in UK and the resisters lead and the caps are made of magnetic materials .
The problem when you order them the new has the same part numbers as the old one .
Just a waste of money !!
I know I tested them !
Greets
Be careful with the new Holco resisters , they sound as a PC of crap.
They no longer made in UK and the resisters lead and the caps are made of magnetic materials .
The problem when you order them the new has the same part numbers as the old one .
Just a waste of money !!
I know I tested them !
Greets